Parallel line spacing device for drawing purposes



July 1, 1952 s. zABoRowsKl PARALLEL LINE SPACING DEVICE FOR DRAWING PURPOSES Filed Jan. 17, 1951 billy/Z4 Y Invenlor Bymk/Bm A itorneyg Patented July 1, 1952 UNITED STATES PATENT` OFFICE l f Y ,2,601,7274 Y t Y i PARALLEL LINE srAonve nevica Foa j DRAWING PURPOSES stefan zabomwski. Waltham cross, England Application January 17, 1951,` serial' No. `206.362

In Great Britain J anuary 19, 1950 This invention relates to devices for facilitating' According to the invention a devicefor `facilitating the drawing of parallel lines on technical drawings andy the like comprises in combination; a set square having formed therein parallel. to the hypotenuse side thereof an enclosed 'sli-jt; a strip member olf smaller length than? the lsaid slot arranged toslide-longitudinally therein; at least oninclined ramp formed on "said strip; resilient meansv secured on said 'setrsquare and engaging said strip member so as normally to urge it intoabutment with one end` of said slot; andi `a vdepressibl'e bridge member carrying at least one roller forengagement with said inclined` rampsaid bridge member being arranged forkmanualdepression to-:presssaid strip mem'- ber into non-sliding engagement with the surface being ruledand at the same time to relievethe pressureon said set square'and allow movement thereof relative `to `said lstrip" `member against the. action of said resilient `means livhilst said roller moves downsaid ramp,.the reduction of the pressure of said bridge member permitting return of said strip member to its original position under the action of` said resilient means in readiness for a `further operation.

According to a further feature of the invention the surface' of the set vsquare and/or the strip member which comes intocontact with the drawing o'r the like on which it is employed s wholly or partly covered with a layer of material which gives an increased coefficient of friction between the set square and the' surface of `the drawing;

According toa further feature'of the invention': means are provided for varyingwithin limits' the interval between successive parallel-lines 11 Claims. (crea-110i 'j Fig. 4 is a plan of Fig.

In carrying the" invention into effect according to one form thereof as shown in Figs. 1 and 2, arset square l, for example a.45 set square, hasformed therein, parallel to and near .the

' hypotenuse side 2 thereof, a rectangular slotx3.

Within'the said slot 3 there is arranged a strip member 4 which is shorter than the slot, one end 4a of said strip member having secured thereto one end of a resilientmeans such as for example, a clock spring 5, the other end of which is anchored to the upper surface of ther set square at 6. Formed integral with the strip member 4 at either end thereof are two inclined ramps 4b. Arranged above and parallel to the said slot 3 is a resilient bridge member 'l consisting of a exible strip of metal or other material bent downwardly atV its end and bolted at either end to the body of the set square. The portion of the bridge member lying over the said slot has secured thereto a pair of spaced brackets 8 carrying rollers 9 the axes of whichrare at right angles to the longitudinal axis of the slot 34 and thestripv member 4.

The stop ll is secured in the desired position by' means' of a clamping screw I4 mounted in a block l5 secured to the set square l.

The under surface ofthe strip member and the body of the set square or portions thereof may be wholly or partly covered with fabric or other material I3 which will provide a high coec'ient along one edge thereof.

of friction between the said set square l or the strip member 4 and the surface over which it is to be moved. Alternatively, the under surface of the set square l and the strip member 4 may be.

suitably roughened or corrugated so as to provide the necessary degree of frictional contact with the surface of the drawing.

vIn thev use of the apparatus shown in Fig. 1 the adjustable stop member Il is rotated about its pivot `l2 so as to limit the movement of the strip member 4 in the slot 3 to an amount equal to that' by which itis desired to space the parallel lines to be drawn with the apparatus, the stop being secured in its adjusted position by the clamping screw 14. The set square is then placedon the surface of the drawing, slight pressure, sufficient only tohold the set square in position being ex erted onthe bridge member fl, and a line drawn The resilient bridge member' 1 islthen pressed downwardly at or near its` central point so as to bring the rollers 9 into contact with the ramps 4b such action pressingv the strip member -4 into rm contact with the drawing and also relieving the pressure of the set 3 square on the latter. Under continued downward pressure on the bridge member 'l the rollers move downwardly along the ramps 4b thus causing lateral movement of the set square relatively to the strip member 4 until the end of the strip member 4 abuts the end of the slot 3, this lateral movement being determined, as stated above, by the adjustment of the stop member The set square moves freely over the drawing during such movement since its pressure thereon is relieved, as stated above, by downward pressure on the bridge member l, whilst the strip member 4 is` securely retained in position on the drawing by the downward pressure exerted thereon through the rollers 9. The pressure applied to the bridge member 'l is then reduced and the rollers are thereby lifted off the inclined ramps 4B of the strip member 4 and the latter, under the action of the spring 5 returns to its original position abutting one end of the slot 3. The set square does not move during said movement of the strip member 4 since the bridge member 'l is no longer acting to relievevthe pressure on the set square and the covering I3 of fabric or other material on. the under surface of the set square I ensures good frictional contact with the surface of the drawing; moreover, a slight manual pressure is still being applied to the bridge member 1, and therebyy to the set square In this position another line can now be drawn along one edge of the set square and the sequence of operations just described can now be repeated for drawing a further ,series of parallellines. v

1 In vthe second form of construction shown in Figs. Sand lv the set square 2| is formed with an enclosed slot 23 in whichis slida'bly disposed a strip member 24 the length of which is smaller than the lengthA of the slot Y23. The strip member 2.4 is formed intermediate its ends with an inclined ramp :24h and is urged in a direction to abut one lend of said slot by'means of a spring 25 one end of which is anchored in arecess Zia, on the set square 2| and the other end of which engages in a recess 24o at one end of the strip member 24.l Pivotally mounted on the set square at either side of the slot 23 and intermediate the endsthereof is a bridge or Ytrigger member 21 extending longitudinally of the slot 23 and formed with a downwardly extending bracket 28 carrying a roller 29.

As in the form of construction shown in Fig. 1 the strip member 24 may likewise Ibe p rovided with means for adjusting the movement of the strip member 24 longitudinally of the slot 23.- IIfhus the strip `member 24 is provided withY a recessed portion providing a straight edge 30 at an angle tothe longitudinal axis of the strip member 24 whilst mounted at one side of the slot l23 and co-operating with the sloping edgein the strip member 24 is a pivotal stop 3| rotating about a pivot 32 and adapted to be se-l cured by aA clamping screw 34 mounted on a bloclc35l I'n thefp'eration of the form of construction of the invention shown in Figs. 3 and 4 the set square 2| is normally kept in firm contact with the drawing by light manual pressure thereon near the trigger memberrpivot. When it is desired to effect movement of the set square for the purpose of drawing spaced parallel lines along one edge` thereof the |bridge or trigger member 21 is depressed at its free end by manual or digital pressure and the pressure on the set square is counteracted bythe leverage vexerted member 21.

4 thereon through the bridge member 2l, the roller 29 acting as a fulcrum. The downward pressure at the same time ensures that the strip member 24 is pressed rmly on the drawing and as the pressure is continued the roller 29 moves down the inclined ramp 24D thereby effecting movement of the set square 2| relative to the strip member 24. AtV the conclusion of such movement, determined bythe amount lof travel of the strip member 24 in the slot 23 determined by the adjustment of the stop member Il, the pressure on the bridge member 2l is released and the light manual pressure on the set square 2| (which is never completely removed during use of the device) is again applied since it is no longer counteracted by pressure on the bridge The strip member 24 then returns under the action of the spring 25 to its original position abutting one end of the slot 23, the roller travelling up the ramp 24h and the apparatus then being ready for a further operation for drawing another series of parallel lines.

It will be obvious to a person skilled in the art that many modications may be made to the apparatus described without departing fromA the invention as dened in the accompanying claims. Thus, many different forms of spacing adjustment could be providedthe form of the resilient means, and its method of attachment to the strip member and set square, and the shape and construction of the bridge member may be other than those described and illustrated herein.

Iclaim:

1. A device for facilitating the drawing of spaced parallel lines comprising in combination: a set square having formed therein parallel to the hypotenuseside thereof an enclosed slot; a strip member of smaller length than the. said slot arranged to Yslide longitudinally therein; at least one inclined ramp formedon said strip; resilient means secured on said setsquare and engaging said strip member so as to urge .it-into abutment with one end .of saidslot; and ,a .de-,. pressible bridge member carrying at least one roller for engagement with said inclined ramp; said bridge member being arranged for'manual depression to press said strip member into none sliding engagement with the surface being ruledand at the same time to relieve the pressure of said set square andl allow movement thereof relative to said strip member against the action of said resilient means whilst said rollerimoves down said ramp the reduction of the pressure on said bridge member permitting return of said strip member to its original. position under the action of said resilient means inreadiness for a furtheroperation. .i .Y

2. A device for facilitating the drawing of spaced parallel lines comprising in combination; a set square having formed therein parallel to.`

square relative to said strip jmember, as said.

4. A device for facilitating the drawing of spaced parallel lines as claimed in claim 2 including the provision of roughened portions on a part at least of the under surface of said set square so as to increase the coefficient of friction thereof.

5. A device for facilitating the drawing of spaced parallel lines as claimed in claim 2 including the provision of an adjustable stop member on said set square to limit the extent of movement of said strip member in said slot.

6. A device for facilitating .the drawing of spaced parallel lines as claimed in claim 2 including a stop member pivoted on said set square and adapted to co-operate with an edge formed on said strip member at an angle to the longitudinal axis thereof, so as to limit the extent of movement of said strip member in said slot; and locking means for securing said stop in its adjusted position.

7. A device for facilitating the drawing of spaced parallel lines comprising in combination a set square having formed therein parallel to the hypotenuse side thereof an enclosed slot; a strip member of smaller length than said slot arranged to slide longitudinally therein; an inclined ramp formed on said strip intermediate the ends thereof; resilient means secured on said set square and engaging said strip member so as to urge it into abutment with one end of said slot; a depressible bridge member pivoted at one Cil end on said set square; and a roller carried on said bridge member intermediate its ends, said roller being arranged so that upon depression of the free end of said bridge member said roller contacts said ramp on said strip member and presses it downwardly and thereafter travels down said ramp whilst counteracting pressure on said set square and thereby produces movement of the latter relative to said strip member, said strip member returning to its original position under the action of said resilient means upon release of pressure of said bridge member.

8. A device for facilitating the drawing of spaced parallel lines as claimed in claim '7 including the provision of a layer of material applied to a portion at least of the under surface of said set square to increase the coefficient of friction thereof.

9. A device for facilitating the drawing of spaced parallel lines as claimed in claim 7 including the provision of roughened portions on a part at least of the under surface of said set square so as to increase the coeicient of friction thereof.

10. A device for facilitating the drawing of spaced parallel lines as claimed in claim '7 including the provision of an adjustable stop member on said set square to limit the extent of movement of said strip member in said slot.

1l. A device for facilitating the drawing of spaced parallel lines as claimed in claim '7 including a stop member pivoted on said set square and adapted to co-operate with an edge formed on said strip member at an angle to the longitudinal axis thereof, so as to limit the extent of movement of said strip member in said slot; and locking means for securing said stop in its adjusted position.

STEFAN ZABOROWSKI.

No references cited. 

